The aim of this international, multicenter, randomized, masked, placebo-controlled trial is to ascertain the efficacy of indomethacin prophylaxis given before 6 hours of age in reducing the mortality rate and the frequency of neurodevelopmental morbidity for premature infants who weight less than 1000 grams at birth. Specifically infants will be randomized to receive three doses of indomethacin or saline placebo at 24 hour intervals. Data pertinent to the study will be collected during the initial hospitalization.